1u04
From Proteopedia
Crystal structure of full length Argonaute from Pyrococcus furiosus
Structural highlights
FunctionAGO_PYRFU A DNA-guided ssDNA endonuclease that may play a role in defense against invading mobile genetic elements. Uses short 5'-phospho-ssDNA sequences as guides (gDNA) to bind complementary target strands, resulting in cleavage of the target DNA (tDNA). Endonucleolytically cleaves DNA in short dsDNA (the gDNA indicates where to cleave on the tDNA). Efficient guide-dependent target DNA cleavage requires a minimal gDNA length of 15 nucleotides (nt) and works up to at least 31 nt. Overexpression decreases plasmid transformation efficiency. Has no appreciable activity with gRNA or on target RNA. Also has guide-independent activity on plasmid DNA called 'chopping' (PubMed:25925567). The cleavage site is 10 nucleotides (nt) downstream of the target residue base-paired with the 5'-end of the gDNA, cleavage is insensitive to adenine methylation. DNA cleavage produces 5'-phosphomonoesters (as it can be ligated by T4 DNA ligase) (PubMed:28165224).[1] [2] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedArgonaute proteins and small interfering RNAs (siRNAs) are the known signature components of the RNA interference effector complex RNA-induced silencing complex (RISC). However, the identity of "Slicer," the enzyme that cleaves the messenger RNA (mRNA) as directed by the siRNA, has not been resolved. Here, we report the crystal structure of the Argonaute protein from Pyrococcus furiosus at 2.25 angstrom resolution. The structure reveals a crescent-shaped base made up of the amino-terminal, middle, and PIWI domains. The Piwi Argonaute Zwille (PAZ) domain is held above the base by a "stalk"-like region. The PIWI domain (named for the protein piwi) is similar to ribonuclease H, with a conserved active site aspartate-aspartate-glutamate motif, strongly implicating Argonaute as "Slicer." The architecture of the molecule and the placement of the PAZ and PIWI domains define a groove for substrate binding and suggest a mechanism for siRNA-guided mRNA cleavage. Crystal structure of Argonaute and its implications for RISC slicer activity.,Song JJ, Smith SK, Hannon GJ, Joshua-Tor L Science. 2004 Sep 3;305(5689):1434-7. Epub 2004 Jul 29. PMID:15284453[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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